The mean, also called the arithmetic mean or the average, is simply the sum of all the data points divided by the number of points. The formula for the mean is displayed on the right.
For example, here are the number of hours that some students worked on a project:
The average time spent working was:
The average is the most common way of calculating central tendency. Some of its characteristics are:
- easy to calculate
- only one exists for any data set
- affected by all observations and, therefore, strongly affected by outliers
- used in many statistics calculations
